Improvement in preparing wood for paper-pulp



UNITED STATES PATENT OFFICE.

MILTON D. VHIPPLE, OF CIIARLESTOVN, MASSACHUSETTS.

IMPROVEMENT IN PREPARING WOOD FOR PAPER-PULP.

Specification forming part of Letters Patent No. 12,978., dated May 29,1855.

To all whom it may concern:

Be it known that I, MILTON D. WHIPPLE, of Charlestown, in the county ofMiddlesex and State of Massachusetts, have invented a new and usefulMethod of Preparing Paper- Pulp from lVood, of which the following is afull, clear, and exact description, reference being had to the annexeddrawings, making part of this specification, in which- Figure l is aside view of the machine which I employ in carrying out my invention;Fig. 2, a vertical section through the center of the same.

In the attempts that have heretofore been made to employ the fiber ofwood as a material in the manufacture of paper various plans have beenadopted for the purpose of disintegrating the wood, none of which haveproved entirely successful. To accomplish this end without deterioratingthe quality of the fiber is the object of my present invention, thefirst part of which consists in submitting the wood in blocks to theaction of a grindstone, by which means it is reduced to pulp of a veryuniform quality, the fibers being linely divided longitudinally, whilethey are preserved of a sufficient length to insure the greateststrength.

The second part of my invention consists in so applying the block to thegrinding-surface that the motion of the latter shall be in the directionof the fibers, or very nearly so, whichposition of the block is found tobe essential to the preservation of the fibers, any other position ofthe blocks with respect to the stone being found to be destructive tothem and to the quality of the pulp obtained therefrom. I have alsodiscovered that it is absolutely essential to the proper performance ofthe operation that the block be kept constantly rotating so as topresent a very limited surface of the block to the stone, and thisrotation of the block of wood While it is being abraded by the stoneconstitutes the third part of my invention.

To enable others skilled in the art to understand my invention and toput the same into practical operation, I will proceed to describe themanner in which I have carried it out. In Athe accompanying drawings, Arepresents a grindstone secured to the shaft B and driven by powersuitably applied to the driving-pulley C.

D is a stationary trough which entirely surrounds t-he stone andcollects and delivers through the spouts E the fibers of the Wood asthey are ground off.

The wood to be ground is divested of its bark and sawed into shortcylinders F. These cylinders are suspended so as to revolve upon theiraxes in contact with the stone in frames constructed as follows:

G is a bar or shaft pivoted in the stationary bearings I'I, attached tothe trough D.

I is an arm mortised into the bar G or otherwise secured thereto, and K'is a similar arm pivoted at a and drawn toward the arm I by the springL. Between these two arms the block to be ground is pivoted, and it iskept uniformly pressed down upon the stone A by means of the springs M.A

The blocks are constantly rotated, While the grinding proceeds in thefollowing manner:

N are stationary sleeves which surround, the driving-shaft '13, butWit-hout touching it, and are secure to the framework of the machine.

P are eccentrics secured to the shaft B, and seen in blue in thedrawings, upon which restthe short posts Q, dotted in red. These postsbear upon the under side of the levers O, pivoted at b to the sleeves N.To these levers are again pivoted other levers R, having inclined teethc upon their inner surfaces,which bear against the blocks or cylindersF.

S are bands of india-rubber, (seen in brown in the drawings,) whichencircle the levers O and draw them constantly toward the sleeves N,keeping the posts Q down upon the surface of the cams P.

T are springs which keep the levers R pressed up against the blocks F.Any other suitable form of spring may be employed for the performance ofeither of these duties.

The cams P are so arranged upon the shaft B that as one of the levers Rmoves out the other moves in. As they move out, the corners of the teethc catch in the block and revolve it. On returning they slip over thesurface of the block and impart no motion thereto. The blocks are thus.kept constantly in motion, as required.

A stream of water is made to pour from the pipe NV upon the stone at thepoint Where the block touches it to insure its even and efficientact-ion upon the fibers of the wood.

One of these pipes seen in the drawings, represented in blue. A similarpipe is required for each block.

It is found to be essential tothe success of the operation that theblock be so placed upon the stone that the fibers shall lie in thedirection of its motion, or very nearly so. Then this correspondence isexact, pulp With the longest fiber is produced. lVhen the blocks areslightly canted, so that the fibers form an angle with the direction ofmotion of the stone, the fiber is shorter, and if this angle beconsiderable the fibers of the pulp are Very short; and when thedirection of motion of the stone is allowed to make an angle of ninetydegrees with the fibers of theblock the latter are cut up so short as tobe Worthless.

In the machine above represented and described three blocks of Wood areshown upon each side of the stone. It is my intention,

however, to apply as many of them upon each side as can be accommodatedaround the pe riphery of the stone, and I do not therefore limit myselftO any particular number Of blocks. Neither do I limit myself to theemployment of the machinery herein described, but intend to vary it ascircumstances may require or as may be found most desirable'.

What I claim as my invention, and desire to secure by Letters Patent inthe process of preparing' paper-pulp from wood, is-

l. Grinding the block upon the surface of a revolving stone or itsequivalent, for the purpose set forth.

2. llIaintaining the block in such position with respect to the stonethat the bers of the Wood shall lie in the direction of motion of thestone, or Very nearly so, for the purpose set forth.

3. Rotating the block during the Operation of grinding, for the purposeherein set forth.

MILTON D. IVHIPPLE,

Witnesses:

SAM. COOPER, JOHN S. GLOW.

